<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    h2 {
      color: red;
    }
  </style>
</head>

<body>
  <div id="app"></div>
  <template id="my-app">
    <h2>你好</h2>
  </template>
  <script src="../lib/js/vue.js"></script>
  <script>
    const App = {
      template: '#my-app',
      data() {
        return {

        }
      },
      methods: {

      }
    }
    const app = Vue.createApp(App)
    app.mount("#app")
  </script>
</body>

</html>